The present invention relates to a vehicular cooling system and a related method for cooling heat radiators mounted on a vehicle.
In a state-of-the-art, is has been proposed to provide a technology for injecting water to be supplied to an outer surface of a condenser in order for a heat radiation capability of the condenser to be improved in a vehicular air conditioning apparatus (see Japanese Utility Model Provisional Publication No. 6-64029). This technology features that, when pressure at a high pressure side in a coolant circuit, detected with a pressure sensor is developed beyond a given threshold, a pump is driven to initiate water injection through a nozzle.
By the way, a state-of-the-art fuel cell system is comprised of a heat radiator that cyclically supplies coolant water to a fuel cell to cool the same and a heat radiator for cyclically supplying coolant water to a recapturing condenser that recycles water from exhaust gases emitted from the fuel cell for moistening the fuel cell. With such a structure, since the plural heat radiators are required to be supplied with water at different time instants because of different cooling requirements of the respective heat radiators in the related art technology, the vehicle must carry a large volume of water in order for a sufficient cooling effect to be achieved in the vehicle propelled with the fuel cell. This results in a bulky and heavy overall size in structure while increasing fuel consumption.
Further, in order to keep a stabilized electric power generating efficiency of the fuel cell, while the coolant water temperature must be maintained in a limited range of given values at an inlet of the fuel cell, the presence of conduits located in a remote distance between the heat radiators and the fuel cell causes a delay in response from one state where water is supplied to the heat radiators and lowers the coolant temperature to another state to lower the coolant temperature at the inlet of the fuel cell at a desired level.
It is therefore an object of the present invention to provide a vehicular cooling system and a related method that address the above issues encountered in the related art practice and which is able to effectively cool a plurality of heat radiators without the need for a large volume of water.
In order to achieve the above object, according to an aspect of the present invention, a vehicular cooling system comprises a heat radiator cooling a heat source mounted in a vehicle, a water supply unit supplying water to an outer surface of the heat radiator, a demanded radiation-heat value detecting unit detecting a radiation-heat value demanded by the heat radiator, and a cooling effect detection unit detecting whether the heat radiator is promising to have a cooling effect when an outer surface of the heat radiator is supplied with water. A control unit is operative to drive the water supply unit such that water is supplied to the outer surface of the heat radiator for cooling the same in response to detected values of the demanded radiation-heat value detecting unit and the cooling effect detection unit.
According to another aspect of the present invention, a vehicular cooling system comprises heat radiator means for cooling a heat source mounted in a vehicle, water supply means for supplying water to an outer surface of the heat radiator, demanded radiation-heat value detecting means for detecting a radiation-heat value demanded by the heat radiator, cooling effect detection means for detecting whether the heat radiator is promising to have a cooling effect when an outer surface of the heat radiator is supplied with water, and control means for driving the water supply means to allow water to be supplied to and to cool the outer surface of the heat radiator means in response to detected values of the demanded radiation-heat value detecting means and the cooling effect detection means.
According to a further aspect of the present invention, there is provided a method of cooling a vehicular heat source, which comprises preparing a heat radiator that cools a heat source mounted in a vehicle, preparing a water supply unit that supplies water to an outer surface of the heat radiator, detecting a radiation-heat value demanded by the heat radiator, detecting whether the heat radiator is promising to have a cooling effect when an outer surface of the heat radiator is supplied with water, and controlling the water supply unit in response to detected values produced in the demanded radiation-heat value detecting step and the cooling effect detecting step, respectively, such that water is supplied to the outer surface of the heat radiator for cooling the same.